Each year more "greenhouse gases" (chiefly carbon dioxide and methane)
are building up in the Earth's atmosphere, creating conditions that
physicists say must eventually lead to a warmer planet. Global warming
will be humanity's greatest challenge because the buildup of gases is
continuing year after year but the warming effects are masked by other
pollutants (mainly sulfur particles) that have blocked out some
sunlight and caused a counter-trend of cooling. (See RHWN #300.) Thus
things look and feel normal even though trouble is brewing on a global
scale. Eventually the warming trend will overwhelm the cooling trend,
and the planet's temperature will rise noticeably. A modest rise is
already measurable; the temperature of Earth has climbed 1 degree
Fahrenheit (F) since 1880. However, by the time scientists all agree (a
decade or two from now, most likely) that the temperature of the Earth
has risen BECAUSE OF a buildup of greenhouse gases, it will be too late
to achieve easy or gradual solutions.

The global warming problem is not like the depletion of Earth's ozone
layer (see RHWN #285). When scientists in 1974 said we should be
looking out for evidence of ozone loss in the upper atmosphere, the
skeptics sneered. Then in 1985, NASA [the National Aeronautics and
Space Administration] measured a gigantic "ozone hole" over the South
Pole and from that moment onward the existence of the ozone depletion
problem has not been seriously challenged, at least not by scientists.

On the other hand, global warming will be harder to prove because there
will be no single "smoking gun" event to galvanize public attention the
way discovery of the ozone hole did. The temperature of the planet is
creeping upward, but is this definitely caused by greenhouse gases?
Maybe, maybe not. While the debate goes on, the buildup of gases
inexorably continues.

What evidence could prove the existence of this problem? Many
researchers believe that the first real evidence of global warming will
be increased variability in the climate--greater swings of high and low
temperature; larger hurricanes, typhoons and cyclones; more tornadoes;
drier and longer droughts; more and bigger floods. Have weather and
climate events of the past decade offered any evidence of extreme
variations?

A new study by Douglas Cogan[1] summarizes evidence from the 1980s and
1990s of climatic instabilities in the U.S. and elsewhere. Cogan
reports record-breaking cold and warmth; extremes of barometric
pressure; record numbers of tornadoes; unprecedented hrricanes and
tropical cyclones; record gales; near-record drought and wetness;
record-breaking heat in Europe; and miscellaneous strange record-
setting events such as snows in places that have never before
experienced snow during recorded history.

These events do not "prove" that global warming has begun. But if more
such events occur in the next few years, it seems likely that skeptics
may begin to agree that global warming is upon us, and that we need to
take rapid steps to phase out coal and oil (the main sources of
greenhouse gases) and phase in renewable forms of energy that won't
leave a legacy of unmanageable wastes and won't heat up the planet--
namely solar power.

Clues to climate-change come in many forms: the oceans are getting
warmer. Coral reefs are blanching. The sea level is rising. Average sea
level has risen 4 to 8 inches since 1900; now it appears to be rising
at the rate of one inch per decade. The extent of polar sea ice has
shrunk about 6% globally in the last 15 years. The Rhone Glacier in
Switzerland, the Grinnell Glacier in Montana's Glacier National Park,
the Mt. Quelccyaya Ice Cap in Peru, and the Speke Glacier in the
Ruwenzori Range in Uganda are among dozens of famous glaciers around
the world that are receding at record rates. Snow cover throughout the
Northern Hemisphere has shrunk 8% since 1973, to its lowest amount in
the 19 years such records have been kept. [pg. 22]

During the summer of 1988 a dome of high pressure covered more than
half the U.S. and Canada. Inside the dome, temperatures soared 6 to 12
degrees above normal. The jet stream, with its parade of rainstorms,
veered around the dome, reducing precipitation beneath the dome to less
than 40% of normal. The resulting heat and drought cut the U.S. corn
crop by 34%; soybean production fell 21% and the wheat harvest slipped
14%. Congress subsequently approved $4 billion for what the President's
Interagency Drought Policy Committee called "the largest disaster
relief measure in U.S. history." [pg. 20]

Conditions in Europe have been similar. A localized drought began in
the Alps in the mid-1980s, spread to several European nations in 1988,
and then encompassed almost the entire continent in 1990. Temperatures
ran more than 10o F above normal for weeks at a time. [pg. 21]

December 1989 was the coldest December on record for 15 states east of
the Mississippi and the fourth coldest December for the nation as a
whole. However the next month, January 1990, was the warmest January on
record for the entire country. At the end of 1990 the western states
experienced the coldest December ever. Though 1990 was the warmest year
ever recorded California's citrus growers lost $750 million in the
December deep freeze. [pg. 43]

The winter of 1991-92 was the warmest winter on record with
temperatures 4o F above normal nationwide and 11o F above normal in the
upper midwest. There was almost no snowfall outside the mountainous
region of the country. But a freak storm in May provided northern
Georgia with its largest snowfall ever recorded. Other parts of the
world that rarely get snow had plenty of it during 1991-92: Jerusalem
received 2 feet of snow; Shanghai had a rare snow shortly after
Christmas; it snowed on Cyprus for the first time in 40 years, in
Beirut for the first time in 55 years and in Eliat, Israel for the
first time in recorded history. [pgs. 44-45]

Normally barometric pressure rises and falls within a narrow band
between 29 and 31 inches of mercury. Cold, dense air pushes the
barometer up; warm, moist air drives it down. During a five-month
period between late 1988 and early 1989, both records--the all-time
high and the all-time low barometric pressure for North America--were
broken. [pg. 45]

In the U.S. in 1990, the National Weather Service reported a record
number of tornadoes (1115 twisters occurring in 44 states); the
previous record was 1102 in 1973. The next year, 1991, set another new
record (1141 tornadoes), though improved detection may account for part
of the increase. The severity of tornadoes also appears to be
increasing, with 14 tornadoes in 1990 reaching F4 and F5 on the Fujita
scale, 3 of them with winds reaching 260 mph.

Hurricanes draw their strength from the heated surface layers of the
sea. The warmer the sea, and the deeper the heated layer, the more
powerful the storm will be. Hurricane Gilbert (1988) was the strongest
hurricane ever recorded in the Atlantic. Hurricane Hugo in 1989 set a
new record for sustained wind speeds (more than 200 miles per hour).
Hurricane Andrew in 1992 was "one of the century's most powerful
hurricanes." (NY TIMES August 26, pg. A1.) A tropical cyclone that
struck Bangladesh in 1991 was the most powerful storm ever to ply the
Bay of Bengal. Known only as Cyclone 2B, it reached sustained winds of
up to 200 mph shortly before it struck land. A 20-foot tidal crest
ushered the storm ashore where it killed 140,000 people. [pg. 46]

Seven typhoons struck Japan in 1991, including Mireille, which killed
50 people and caused more damage to insured property than any other
storm in that nation's history. The '90s do seem to be shaping up as a
time of unparalleled storms.

Three successive gales struck Great Britain and the European continent
in late January and early February 1990, with sustained winds of 100
mph. These storms were unprecedented in European memory. During that
same period, the jet stream accelerated to 230 mph over the north
Atlantic--as fast as it has ever been measured there. [pg. 46]

Before these gales struck, the concern in Europe and the U.K. had been
drought. The water table as measured at West Sussex, England--the
longest continuous observation site in the world--was within an inch or
two of the lowest level ever recorded as of mid-December 1989. But the
winter of 1989-90 was the wettest winter in 70 years. February, 1990,
was the wettest February ever. The water table in West Sussex rose 125
feet in just 8 weeks, an unprecedented rise in the 150-year history of
the site. Despite the wet February, 1990 turned out to be the second-
driest year of record in England, though in Scotland 1990 was the
wettest year ever recorded. March through September was the driest
spring and summer period for England and Wales in a rainfall series
dating back 220 years. "[T]here is no modern parallel to the remarkable
swings in water resources recently experienced," two researchers wrote
in WEATHER, the journal of the Royal Meteorological Society.

Heat has also set records in England in recent years. Three consecutive
winters, starting in 1987-88, constitute the warmest "triplet" of
winters in 332 years of record-keeping. Almost every month during 1989
and 1990 was warmer than normal, making it the warmest two-year period
in a record dating back to 1659.

Cogan offers considerably more evidence of recent chaotic weather,
which we haven't space to report here. We merely note that the dollar
cost of extreme weather is already great and is evidently growing.
Witness the $15 to $30 BILLION estimate for repairs following hurricane
Andrew in Florida and Louisiana in 1992.

Carbon dioxide, the main greenhouse gas, remains in the atmosphere for
a long time. CO2 released today will destabilize the atmosphere for our
grandchildren. Each day of delay makes needed solutions more drastic,
more expensive and more difficult to implement.

THE RESPONSIBLE PARTIES ARE COAL AND OIL EXECUTIVES WHO STEADFASTLY
OPPOSE CHANGE. THE SOLUTION IS SOLAR TECHNOLOGIES, WHICH ARE ALREADY
AVAILABLE. THE LEAST-COST TIME TO BEGIN THE TRANSITION IS NOW